#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include <math.h>
int main() 
{
    double n = 0;
    int m = 0;
    while (scanf("%lf%d", &n, &m) == 2) 
    {
        double sum = 0;
        for (; m > 0; m--) {
            sum += n;
            n = sqrt(n);
        }
        printf("%.2lf\n", sum);
    }
    return 0;
}